Sail-World's resident photo and videographer, John Navas, was out on the water today and captured video of Emirates Team NZ's AC72 sailing a close reach - near windward course while foiling.

Speed is dramatic - 30-35kts clocked off the chasing powerboat - compared to the usual 20-23kts seen in racing to date.

Note in the still shot above, the leeward hull is clear of the water, but a significant part of the foil is immersed - reducing leeway. To achieve reasonable VMG, leeway must be kept to a minimum.

Something for the aficionados to work out is whether foiling upwind, sailing faster and lower (and carefully playing the shifts) is better than slower and higher.

The estimated numbers are:

Course over ground: 300° magnetic. Wind direction: 245° magnetic (TWA 55° - it is not known what the 'normal TWA is for an AC72, but a monohull is 45°). Wind strength: 12-14 kts Sailing angle is reported at 300 degrees.